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LC-26SA1E
CHAPTER 6.
TROUBLESHOOTING TABLE
[1] TROBLESHOOTING TABLE
Power unit operation check.
Are the power cord and harness in the unit properly connected?
YES
Is F701 normal?
YES
Is a voltage of BU5V applied to pin (20) of P701?
(Set the main power SW to OFF.)
YES
Is it a symptom that the relay clatters twice as soon as the main
power SW is set to ON and the power is not supplied?
YES
Does the same symptom appear even if R858 (2.7k) is
removed and the power is supplied again?
YES
Check Q724, D731, D734, IC707, D751, D753, D754,
D741, D759 and D746.
NO
Does a relay noise sound? (Once)
YES
Check peripheral circuits of D738, R828 and D735.
NO
Is a voltage of approx.
8 - 15V to pin (4) of
IC705?
YES
Check short circuit of 5V line (D737,
C752, etc.).
Service Manual
NO
Connect the power cord and harness properly, and turn on the
power.
NO
Are both ends of C704, C707 (26) and C705 (32) short-circuited
when checking their resistance values?
NO
Replace F701.
C704 ••• Check VA701, VA702 and D701.
C707 (26)/C705 (32) ••• Check IC704 and 705.
NO
Check IC705, IC708, D725 and Q724.
Check IC704, D728, D762 and D736. If there are no problems,
check the resistance value between pins (1) and (6) of P704.
NO
When the value is low (several Ω - several hundred Ω),
disconnect P704. If the value is still low, the parts of 24V line are
defective. When the resistance value is several kΩ, check the
inverter unit.
NO
Are PCON1 and 2 [pins (1) and (2) of P702] at Hi (3V or more)?
Check peripheral circuits of Q712, Q713, Q721, Q723
and RY701.
There is a possibility that control by P-CON is not performed
properly. Check whether the "PS-ON" and "PS-ON2" signals are
sent from pins (97) and (91) of IC1710 (FPGA) of MAIN-UNIT.
6 – 1
LC-26SA1E/RU, LC-32SA1E/RU
YES
YES
NO
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